fix(transformer): allow transforming of .cts/.mts extensions. (#3996)

Author: smack0007

src/constants.ts

@@ -1,8 +1,8 @@
 export const LINE_FEED = '\n'
 export const DECLARATION_TYPE_EXT = '.d.ts'
 export const JS_JSX_EXTENSIONS = ['.js', '.jsx']
-export const TS_TSX_REGEX = /\.m?tsx?$/
-export const JS_JSX_REGEX = /\.m?jsx?$/
+export const TS_TSX_REGEX = /\.[cm]?tsx?$/
+export const JS_JSX_REGEX = /\.[cm]?jsx?$/
 // `extensionsToTreatAsEsm` will throw error with `.mjs`
 export const TS_EXT_TO_TREAT_AS_ESM = ['.ts', '.tsx', '.mts']
 export const JS_EXT_TO_TREAT_AS_ESM = ['.jsx']

src/legacy/ts-jest-transformer.spec.ts

@@ -330,7 +330,7 @@ describe('TsJestTransformer', () => {
       expect(process.env.TS_JEST).toBe('1')
     })
 
-    test.each(['foo.ts', 'foo.tsx', 'foo.mts', 'foo.mtsx'])('should process ts/tsx file', (filePath) => {
+    test.each(['foo.ts', 'foo.tsx', 'foo.cts', 'foo.mts', 'foo.mtsx'])('should process ts/tsx file', (filePath) => {
       const fileContent = 'const foo = 1'
       const output = 'var foo = 1'
       tr.getCacheKey(fileContent, filePath, baseTransformOptions)
@@ -345,7 +345,7 @@ describe('TsJestTransformer', () => {
       })
     })
 
-    test.each(['foo.js', 'foo.jsx', 'foo.mjs', 'foo.mjsx'])(
+    test.each(['foo.js', 'foo.jsx', 'foo.cjs', 'foo.mjs', 'foo.mjsx'])(
       'should process js/jsx file with allowJs true',
       (filePath) => {
         const fileContent = 'const foo = 1'